We went to the children's Stations of the Cross service at our local church. It's very interactive with activities at each station ranging from drawing lots to considering grieving mothers of the modern world. It ended with an egg-and-word hunt round the church. They had to work together to rearrange the words into a few sentences that summarised the Easter story.
Following on from plot generators, Boykin found a Mad Libs generator. He typed in his own story and decided which words would be added by other people. He had to identify adverbs, adjectives, verbs and nouns. I had a go too and its not as simple as I thought. I forgot to take plurals and tenses into account so it didn't read quite as well as it should've done, but it was still funny.
I recommend having a go with your own children. It's a funny way to help learn grammar, practise spelling and encourage creative writing :)